Vector a has a magnitude of 12.3 units and points due west. vector b points due north. what is the magnitude of b if a - b has a magnitude of 15.0 units

The magnitude of vector b is 8.58 Unit.

Since both the vectors a and b are perpendicular to each other, so we can apply the Pythagoras theorem to calculate the magnitude of the vector b.

Applying the Pythagoras theorem

(a-b)^2=a^2+b^2

15^2=12.3^2-b^2

b=8.58 unit

Therefor the magnitude of the vector b is 8.58 unit.